MySQL Increment/Decrement

[Ben Miller]

I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?



Thanks in advance.



Ben

[Robert Cummings]

Post by Ben Miller
I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?

You mean:

UPDATE table SET column = column + 1;

?

Cheers,
Rob.

[Bipper Goes!]

UPDATE SQLTABLE SET count = (count+1) WHERE PromoID=1

Is this valid for your issue? I have no way of testing or toying

Post by Ben Miller
I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?
Thanks in advance.
Ben

[Eric Lee]

Ben

It seems that you can just update the column with a update query like this,

update table set field = field + 1 where some condition

This might be the thing you need.


Eric

Post by Ben Miller
I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?
Thanks in advance.
Ben

[muzy]

Hello Ben,

I had the same question yesterday (but with SQLite) and there are at
least 2 solutions.

The first was already mentioned:

UPDATE table SET value = value + 1 WHERE foo = bar;

The second solution which also works is:

UPDATE table SET value = (SELECT value FROM table WHERE foo = bar) + 1
WHERE foo = bar;


I hope it helps.


Greetings from Germany,


Sebastian

Post by Ben Miller
I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?
Thanks in advance.
Ben

[Phpster]

Post by muzy
Hello Ben,
I had the same question yesterday (but with SQLite) and there are at
least 2 solutions.
UPDATE table SET value = value + 1 WHERE foo = bar;
UPDATE table SET value = (SELECT value FROM table WHERE foo = bar) +
1 WHERE foo = bar;
I hope it helps.
Greetings from Germany,
Sebastian

Post by Ben Miller
I hope this isn't a bone-head question - Is there a MySQL query that will
increment/decrement the value in an integer column with a single query - in
other words, I don't have to run a SELECT query to get the value,
add/subtract to/from the value, and then run an UPDATE query to store the
new value?
Thanks in advance.
Ben

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You may run into race conditions and contention when handling auto-
incrementimg this way. Best to isolate the SQL into a transaction to
avoid this

Bastien

Sent from my iPod